The Collaborative International Dictionary
Relieving arch
Relieving \Re*liev"ing\, a. Serving or tending to relieve. Relieving arch (Arch.), a discharging arch. See under Discharge, v. t. Relieving tackle. (Naut.)
A temporary tackle attached to the tiller of a vessel during gales or an action, in case of accident to the tiller ropes.
A strong tackle from a wharf to a careened vessel, to prevent her from going over entirely, and to assist in righting her.
--Totten.
--Craig.